Process for replacing a length of buried pipe
CA 2013658 C · Owner: Campbell, Donald Neil · Inventors: Campbell, David Bruce; Campbell, Donald Neil
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A LENGTH OF BURIED PIPE" ABSTRACT OF THE DISCLOSURE, The process comprises excavating pits at the first and second ends of a buried section of old water main pipe that is to be replaced with new pipe. The exposed segments of pipe are broken up to provide access to the bore of the old pipe. A pipe splitter and a cylinder-actuated pulling unit are installed in the first pit. A string of rods is extended through the old pipe bore from the first pit to the second pit. A tool assembly of sequentially connected components is attached to the second end of the rod string. The tool assembly may comprise: means for centralizing the second end of the rod string in the second end of the old pipe …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed April 2, 1990 and granted April 28, 1992. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 2, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 2, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.